The development of alpha olefin oligomerization techniques for the selective production of linear alpha olefins (C6 to C20) which do not utilize triethylaluminum (TEA) as part of the catalyst system has been a challenge. Both the economics and relative efficiency of TEA-based techniques have been difficult to match in alternative techniques. Some commercial success has been achieved using alternative techniques which use homogeneous catalyst systems; however, these techniques require extended secondary processing to recover the linear alpha olefins from undesired fractions/products such as butene or waxes. Other alternative catalyst systems have been developed for selective ethylene oligomerization. The selective ethylene oligomerization catalyst systems can produce desired linear alpha olefins without the drawbacks of the alternative techniques which use homogeneous catalyst systems. There is an ongoing need for improvements to selective ethylene oligomerization techniques.